2 * max8952.c - Voltage and current regulation for the Maxim 8952
4 * Copyright (C) 2010 Samsung Electronics
5 * MyungJoo Ham <myungjoo.ham@samsung.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/i2c.h>
25 #include <linux/err.h>
26 #include <linux/platform_device.h>
27 #include <linux/regulator/driver.h>
28 #include <linux/regulator/max8952.h>
29 #include <linux/gpio.h>
31 #include <linux/slab.h>
47 struct i2c_client *client;
49 struct max8952_platform_data *pdata;
50 struct regulator_dev *rdev;
57 static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
59 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
66 static int max8952_write_reg(struct max8952_data *max8952,
69 return i2c_smbus_write_byte_data(max8952->client, reg, value);
72 static int max8952_list_voltage(struct regulator_dev *rdev,
73 unsigned int selector)
75 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
77 if (rdev_get_id(rdev) != 0)
80 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
83 static int max8952_is_enabled(struct regulator_dev *rdev)
85 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
89 static int max8952_enable(struct regulator_dev *rdev)
91 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
93 /* If not valid, assume "ALWAYS_HIGH" */
94 if (gpio_is_valid(max8952->pdata->gpio_en))
95 gpio_set_value(max8952->pdata->gpio_en, 1);
101 static int max8952_disable(struct regulator_dev *rdev)
103 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
105 /* If not valid, assume "ALWAYS_HIGH" -> not permitted */
106 if (gpio_is_valid(max8952->pdata->gpio_en))
107 gpio_set_value(max8952->pdata->gpio_en, 0);
115 static int max8952_get_voltage_sel(struct regulator_dev *rdev)
117 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
128 static int max8952_set_voltage_sel(struct regulator_dev *rdev,
131 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
133 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
134 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
135 /* DVS not supported */
139 max8952->vid0 = selector & 0x1;
140 max8952->vid1 = (selector >> 1) & 0x1;
141 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
142 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
147 static struct regulator_ops max8952_ops = {
148 .list_voltage = max8952_list_voltage,
149 .is_enabled = max8952_is_enabled,
150 .enable = max8952_enable,
151 .disable = max8952_disable,
152 .get_voltage_sel = max8952_get_voltage_sel,
153 .set_voltage_sel = max8952_set_voltage_sel,
154 .set_suspend_disable = max8952_disable,
157 static const struct regulator_desc regulator = {
158 .name = "MAX8952_VOUT",
160 .n_voltages = MAX8952_NUM_DVS_MODE,
162 .type = REGULATOR_VOLTAGE,
163 .owner = THIS_MODULE,
166 static int __devinit max8952_pmic_probe(struct i2c_client *client,
167 const struct i2c_device_id *i2c_id)
169 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
170 struct max8952_platform_data *pdata = client->dev.platform_data;
171 struct regulator_config config = { };
172 struct max8952_data *max8952;
174 int ret = 0, err = 0;
177 dev_err(&client->dev, "Require the platform data\n");
181 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
184 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
189 max8952->client = client;
190 max8952->dev = &client->dev;
191 max8952->pdata = pdata;
193 config.dev = max8952->dev;
194 config.init_data = &pdata->reg_data;
195 config.driver_data = max8952;
197 max8952->rdev = regulator_register(®ulator, &config);
199 if (IS_ERR(max8952->rdev)) {
200 ret = PTR_ERR(max8952->rdev);
201 dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
205 max8952->en = !!(pdata->reg_data.constraints.boot_on);
206 max8952->vid0 = pdata->default_mode & 0x1;
207 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
209 if (gpio_is_valid(pdata->gpio_en)) {
210 if (!gpio_request(pdata->gpio_en, "MAX8952 EN"))
211 gpio_direction_output(pdata->gpio_en, max8952->en);
218 dev_info(max8952->dev, "EN gpio invalid: assume that EN"
221 pdata->gpio_en = -1; /* Mark invalid */
226 if (gpio_is_valid(pdata->gpio_vid0) &&
227 gpio_is_valid(pdata->gpio_vid1)) {
228 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
229 gpio_direction_output(pdata->gpio_vid0,
230 (pdata->default_mode) & 0x1);
234 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
235 gpio_direction_output(pdata->gpio_vid1,
236 (pdata->default_mode >> 1) & 0x1);
239 gpio_free(pdata->gpio_vid0);
247 dev_warn(max8952->dev, "VID0/1 gpio invalid: "
248 "DVS not available.\n");
252 pdata->gpio_vid0 = -1;
253 pdata->gpio_vid1 = -1;
255 /* Disable Pulldown of EN only */
256 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
258 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
259 " do not have proper controls.\n");
262 * Disable Pulldown on EN, VID0, VID1 to reduce
263 * leakage current of MAX8952 assuming that MAX8952
264 * is turned on (EN==1). Note that without having VID0/1
265 * properly connected, turning pulldown off can be
266 * problematic. Thus, turn this off only when they are
267 * controllable by GPIO.
269 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
272 max8952_write_reg(max8952, MAX8952_REG_MODE0,
273 (max8952_read_reg(max8952,
274 MAX8952_REG_MODE0) & 0xC0) |
275 (pdata->dvs_mode[0] & 0x3F));
276 max8952_write_reg(max8952, MAX8952_REG_MODE1,
277 (max8952_read_reg(max8952,
278 MAX8952_REG_MODE1) & 0xC0) |
279 (pdata->dvs_mode[1] & 0x3F));
280 max8952_write_reg(max8952, MAX8952_REG_MODE2,
281 (max8952_read_reg(max8952,
282 MAX8952_REG_MODE2) & 0xC0) |
283 (pdata->dvs_mode[2] & 0x3F));
284 max8952_write_reg(max8952, MAX8952_REG_MODE3,
285 (max8952_read_reg(max8952,
286 MAX8952_REG_MODE3) & 0xC0) |
287 (pdata->dvs_mode[3] & 0x3F));
289 max8952_write_reg(max8952, MAX8952_REG_SYNC,
290 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
291 ((pdata->sync_freq & 0x3) << 6));
292 max8952_write_reg(max8952, MAX8952_REG_RAMP,
293 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
294 ((pdata->ramp_speed & 0x7) << 5));
296 i2c_set_clientdata(client, max8952);
301 static int __devexit max8952_pmic_remove(struct i2c_client *client)
303 struct max8952_data *max8952 = i2c_get_clientdata(client);
304 struct max8952_platform_data *pdata = max8952->pdata;
305 struct regulator_dev *rdev = max8952->rdev;
307 regulator_unregister(rdev);
309 gpio_free(pdata->gpio_vid0);
310 gpio_free(pdata->gpio_vid1);
311 gpio_free(pdata->gpio_en);
315 static const struct i2c_device_id max8952_ids[] = {
319 MODULE_DEVICE_TABLE(i2c, max8952_ids);
321 static struct i2c_driver max8952_pmic_driver = {
322 .probe = max8952_pmic_probe,
323 .remove = __devexit_p(max8952_pmic_remove),
327 .id_table = max8952_ids,
330 static int __init max8952_pmic_init(void)
332 return i2c_add_driver(&max8952_pmic_driver);
334 subsys_initcall(max8952_pmic_init);
336 static void __exit max8952_pmic_exit(void)
338 i2c_del_driver(&max8952_pmic_driver);
340 module_exit(max8952_pmic_exit);
342 MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
343 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
344 MODULE_LICENSE("GPL");